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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Diffused Nickel Cadmium is turning orange at edges
I have having an issue with Ni-Cd, after diffusion bake the panels/parts are turning orange at the edges. Any ideas why?
Dan SkinnerMaterials Engineer - Tulsa, Oklahoma
2007
The sacharin brightener in some nickel will turn yellow under heat, but I assume and hope you are using almost pure nickel, like from a sulfamate solution.
The "edges" would be high current density locations. Nickel does not
"throw" as well as cadmium so the nickel would be richer on the edges after baking. When nickel oxidizes it first turns orange, then brown, and finally black.
To get a more balanced distribution of nickel, then get further away from the anodes and raise the pH about 0.2 pH.
Robert H Probert
Robert H Probert Technical Services
Garner, North Carolina
2007
An analysis of the orange powdery coating shows to be mostly cadmium, less than 0.1% Nickel
Dan Skinner- Tulsa, OK USA
2007
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